Multimedia Network Networking Issues

Knowledge assumed prior to starting this module

TCP streams are decomposed into packets for sending
UDP is unreliable
When packets are sent from one host to another the amount of time for the packet to arrive will vary, sometimes significantly. Packets may also be lost, which in the case of TCP means that data will be retransmitted and a delay will result.
The concept of buffering
Knowledge and understanding surrounding bandwidth and latency.

To be able to compare and contrast the delivery and playback requirements between the following multimedia delivery approaches:
- Complete the download and then play
- Streaming of stored media (e.g. a movie or song)
- Live media (e.g. live sporting event or radio broadcast)
- Real-time interactive media stream (e.g. Video or telephone call)
Issues associated with streaming of data
- lost or late data
- playing back at the proper rate
Controlling the stream (i.e. starting, stopping, positioning)
Playback requirements of the stream, i.e how timestamps and sequence numbers are used to ensure proper playback
Handling lost or out of order data ! Issues associated with mobile communication like VOIP, SKYPE and locating participants
(Content distribution and scaling?? Or is this something that is more appropriate for a separate topic or even the next course.)

Pre class Activities
In Class Activities
- Invention exercise - design a streaming protocol to handle playback of a movie, then a live event, then for the ambitious add the control of the stream
- Invention exercise - design a header for a real time transport protocol that runs on top of UDP (i.e. invent RTP) Maybe this is really the same as the previous activity or and extension of it.
After Class Activities

Pre-class Activities
In Class Activities
- Invention activity - design a protocol to control the playback of a realtime stream. (i.e. invent RTSP) We would probably want to list several things that we would expect the students to address in this invention activity, or maybe that is part of the activity.
- Invention activity with respect to device location. (i.e. something like SIP)
- Have students write software/scripts to do a register with a SIP server and a
Post Class Activities
- Assignment from Kurose and Ross. (See: Instructor Resources)

Multimedia streaming assignment from Kurose and Ross The multimedia chapter of Kurose and Ross (Chapter 7 in 4th edition) has a programming assignment that uses RTP and RTSP. The text directs one to a website for the full assignment and supporting materials but I wasn't able to find them. However, the link at the start of this bullet has them. (In case the above website disappears, I have "archived" its contents in the file RTP.tar.gz.
RFC 4566 SDP - Session description protocol.
Java Media Framework
SIP - Session Initiation Protocol
SIP server software
H.323 - ITU 323 incorporates both call signal and multimedia transport on packet switched networks
- H.323 on Wikipedia
- T-REC-H.323-200912-IPDF-E.pdf copied from the ITU. Additional information can be found at: http://www.itu.int/rec/T-REC-H.323/en/
RTSP - Real time streaming protocol - Protocol between client and server that controls the streaming of the multimedia data, but it does not specify how the multimedia is actually streamed, that is handled by a different protocol. Typically RTP.
RTP - Realtime Transport Protocol - A protocol that specifies the packet format and semantics of sending/receiving streaming multimedia data on an IP network
Sample slides Starting about about slide 7 there is a comparison of various multimedia signalling protocols.

Topic attachments
I	Attachment	History	Action	Size	Date	Who	Comment
gz	RTP.tar.gz	r1	manage	41.4 K	2011-06-24 - 00:28	DonaldActon	Multimedia RTP assignment
pdf	T-REC-H.323-200912-IPDF-E.pdf	r1	manage	3759.3 K	2011-06-24 - 18:24	TWikiGuest	ITU H.323 Recommendation
zip	assignment2.zip	r1	manage	6893.6 K	2011-06-28 - 17:09	AlanWagner	Multimedia Assignment from CPSC 417 -- based on Kurose & Ross,

Topic revision: r12 - 2011-06-28 - AlanWagner